When former Gov. Mike Rounds emerged from a crowded Republican primary field last week, it confirmed what had been long expected: Weiland will be facing an opponent with more cash, greater name recognition and stronger national party support. But the Sioux Falls restaurant owner has spent months driving to hundreds of small towns across the state in a style reminiscent of former boss U.S. Sen. Tom Daschle, and he thinks those cafe chats about the need to take back government from big corporations will pay off later.

"I just have to believe that kind of hard work, shoe leather, is going to mean a lot when people go to the polls in November," said Weiland, 55.

Weiland, Rounds and two independents — former Republican U.S. Sen. Larry Pressler and former state lawmaker Gordon Howie — are vying for the seat being vacated by retiring Democratic Sen. Tim Johnson.

The presence of those two independents has the potential to fracture the Republican vote, but Rounds thinks conservatives will unite behind him. He said Republicans, conservative independents and even conservative Democrats want to see change in Washington and bring a Republican majority to the Senate.

"They're going to want to be part of a winning team" said Rounds, 59. "They're going to want to see results. They care deeply about bringing back the United State Senate and taking it away from the majority leader right now."

The South Dakota U.S. Senate race is one of three involving a seat now held by a Democrat— also including West Virginia and Montana — where Republicans believe they have the best chance to win because President Barack Obama lost those states in the 2012 election. Republicans need to make a net gain of six seats to take over the majority in the U.S. Senate.

Of South Dakota's more than 510,000 registered voters at the end of May, 237,000 listed themselves as Republicans, 175,000 classified themselves as Democrats and 83,000 had no party affiliation, according to records from the South Dakota Secretary of State's office. But despite those numbers, South Dakotans have shown they have no problem sending Democrats to the U.S. Senate, as evidenced by Johnson, Daschle, Jim Abourezk and George McGovern.

Pressler, who describes himself as a "passionate centrist," said whether the Senate remains under Democratic control or shifts to Republicans, the chamber will be closely divided.

He said an independent voice with his experience — two terms in the House followed by three Senate terms from 1975 to 1997 — could be an asset for the state.

"An independent could be potentially powerful, and I'll be able to take my seniority back to the Senate," said Pressler, 72. "My biggest job will be to persuade people that an independent can be elected and that he can be an effective voice for South Dakota."

Howie, 64, entered the race as an independent in April but immediately put his campaign on hold to support former state Rep. Stace Nelson in the Republican primary and would drop out if Nelson won. Nelson captured nearly 18 percent of the vote to Rounds' 55 percent.

Howie said he's offering a choice for the 45 percent of Republicans who did not vote for Rounds to back a campaign based on conservative principles including faith and freedom, reigning in spending and cutting taxes.

"We're going to try to provide an alternative to the three moderates who are in the race," Howie said.